Origin point spits clumps of particles
The particle system is based on faces of the boolean intersection between a very narrow cube and the mesh text. The problem occurs when that boolean operation is between letters, creating an empty mesh. The particle system still needs to produce particles at the rate declared (10000 over a few dozen frames) and thus default to producing those particles somewhere at the Origin. May that's a bug... may be not.

Anyway, one workaround is to make the boolean cube (silver) wide enough to never create an empty mesh, i.e. as wide as the widest gap between your letters. This way the particle system will always some geometry to emit particles from instead of emitting from some random location.

Here you can see that with the narrow boolean, particles are emitted at the origin at frame 46 and later when it is in the gap:



And here the particles stopped being emitted at the origin when the boolean cube is wide enough to always intersect with the text object: